The invention generally relates to an electrical terminal block assembly and more particularly to a terminal block assembly configured to receive multiple wire and contact arrangements.
A wide variety of terminal block assemblies exist for use today depending upon the environment and application for which it is intended. In some applications, multiple sets of wires within an end product are joined within the terminal block assembly to external power cords and building wire. Examples of this application may be found in households or in commercial environments, such as restaurants or other businesses that utilize equipment that has high power demands. An example of a household appliance or restaurant appliance that has a high power demand is an electrical range. The manner in which the power cords or building wire are connected within the terminal block assembly is somewhat dependent upon city, state and federal regulations related thereto. For example certain city regulations require particular types of contacts to be securely fixed to the end of power cords installed in the household or commercial building. In other locales, building wires may be dedicated lines with one end being directly connected to the household or building power source (e.g. circuit breaker), while the opposite end is terminated directly to the appliance. In these situations, the building wire are not terminated at the wall in the room at a receptacle, but instead extend into the room to be directly connected to the product. Alternatively, when the building wiring ends at a wall receptacle, a separate “pigtail” type premanufactured power cord may be used to connect the end product to the wall receptacle.
The power cords joined to the end product may have ends that are terminated in a variety of manners. The form of termination may depend upon the applicable codes and regulations. For example, in certain metropolitan areas, power cords are not permitted to be used in any form. Instead, the bare conductor of the building wire is required to be directly attached to the terminal block assembly within the end product. In other applications and/or metropolitan areas the power cord is required to include particular types of contacts on the outer ends, with such contacts satisfying certain electrical and mechanical standards. The shape and configuration of these contacts varies. One example of a contact used with power cords is a ring and tongue configuration in which a base portion of the contact is securely crimped to the conductor of the power cord, while the outer end of the contact includes a washer shaped portion with a hole therethrough.
Heretofore, terminal block assemblies have been developed to be joined with a particular type of contact or alternatively to be joined directly to the bare conductors of the power cord. Examples of such terminal block assemblies are found in U.S. Pat. Nos. 4,273,408 and 4,603,376. The '376 patent discloses a terminal assembly having an opening therethrough to receive the bare conductor of the power cord. A set screw is provided through one side of the opening and, when screwed in, securely retains the bare conductor within the opening of the terminal block assembly. The '408 patent discloses a terminal block assembly having upper and lower plate portions that are joined by a screw. The exposed conductor is sandwiched between the upper and lower plate portions as the screw is tightened within the terminal block assembly. However, the configuration described in the '376 and '408 patents are not well suited to retain power cords having contacts provided thereon such as the ring tongue type contact.
An alternative configuration for a terminal block assembly is disclosed in U.S. Pat. No. 4,236,778. The '778 patent illustrates a terminal block assembly that is configured to receive a power cord having a contact of the ring and tongue type mounted thereto. A terminal is provided with a planer plate portion that receives the ring shaped end portion of the ring and tongue contact. A screw is received through both to securely bind them to one another. However, the terminal block assembly of the '778 patent is not well suited to directly receive the exposed conductors of the power cord.
Consequently, conventional terminal block assemblies have somewhat dedicated applications. A need exists for a terminal block assembly having a more universal configuration.
Further, conventional terminal block assemblies may be difficult to manufacture and may potentially become disassembled over time. In general, conventional terminal block assemblies include a housing formed of an insulative material and shaped to provide one or more regions therein to receive conductive terminal block connectors. Each terminal block connector is configured to join a power line from the end product (e.g. electrical range) and a corresponding power cord from the household or building power source. Each terminal block connector is held within the insulated housing of the terminal block assembly through a separate fastening means, such as rivets, screws, and the like. During construction of the terminal block assembly, manufacturing time is required to rivet or otherwise secure the terminal block connector to the insulated housing. The rivets or other securing members also add to the overall costs of the terminal block assembly. In addition, over the life of the terminal block assembly, the fastening member used to retain the terminal block connectors within the insulated housing may become loose or completely disconnected. Consequently, a need exists for an improved mechanism for retaining the terminal block connectors within the housing of the terminal block assembly.